Vacuum Pumps

Industrial Vacuum Pumps

Single Stage Bare Shaft Liquid Ring Vacuum Pumps

Choosing the correct industrial vacuum pump for your application can be a rather difficult task. Various processes and applications uses different styles of pumps. Below you is a quick comparison chart of the pros and cons of various pump technologies.

For the following reasons shown below, liquid ring pumps are the most frequently used vacuum pumps in the process industry. Rugged, sealed with the process solvents from the process stream, while have very low maintenance requirements are some important features.

If there is not a condensable in the process stream suitable for sealing the liquid ring vacuum pump, or a lower operating pressure is instead desirable, or there simply is not cooling water available, an oil-sealed liquid ring pump is often a good option.

A dry vacuum pump may be a suitable option for applications where there is absolutely no chance of condensation/process carryover or the pump can be protected adequately.  Please note, however, these pumps becomes inoperable if it ingests liquids and/or solids. The repair costs are quite prohibitive.

Rotary vane pumps as indicated by the chart are much less expensive then the other vacuum pumps and ultimately less durable and thus often used in less industrial applications.

Vacuum Pump TypeTypical
Ability to Handle
Process Carryover
Initial Capital CostMaintenance FrequencyRepair Difficulty
Liquid Ring Water or Solvent-Sealed> 30 Torr*HighCooling WaterMediumLowLow
Liquid Ring Oil-Sealed> 15 Torr*High
(Oil may get contamintated)
Dry Screw> 0.1 TorrLow to MediumSmall Amount of Water and Purge GasHighLowHigh
Oil-Lubricated Rotary Vane1 - 150 TorrLowNoneLowHighLow
Rotary Piston0.001 - 100 TorrMediumNoneLow to MediumMediumHigh

*With additional technology, liquid ring operating range can extend down to 0.03 Torr